1. Field of the Invention
The invention relates to piercing structures and refers more particularly to a piercing structure of relatively small diameter capable of exerting extremely high pressures due to a plurality of separate axially spaced apart and aligned pressure chambers therein, whereby particularly heavy workpieces may be readily pierced at relatively close intervals of spacing.
2. Description of the Prior Art
The piercing structure of the invention is similar to the piercing structure disclosed in U.S. Pat. No. 2,841,117. The piercing structure of the invention is an improvement over prior piercing structures in that, for example, three separate axially aligned pressure chambers are provided in the piercing structure of the present invention which increases the available pressure in the piercing structure for a given diameter.
With the piercing structure of the current design, it is thus possible to provide increased pressure necessary to pierce large diameter openings in thick hard metal plates.